The new undersea cable systems are now capable of 18 terabits per fiber pair. It is interesting how combinations of bits are being represented by combinations of optical features.
http://www.lightwaveonline.com/articles/print/volume-30/issue-5/features/which-optical-modulation-scheme-best-fits-my-application.html Roderick Beck Director of Global Sales United Cable Company www.unitedcablecompany.com<http://www.unitedcablecompany.com>

